The UN Special Rapporteur on Torture, Professor Nils Melzer, and Dr Natasa Mavronicola at the UN.

As indicated in the relevant press release, the report highlights that any unnecessary, excessive or otherwise arbitrary use of force by law enforcement officials is incompatible with the absolute prohibition of cruel, inhuman or degrading treatment. Additionally, where such force intentionally and purposefully inflicts pain or suffering on powerless persons it is conclusively unlawful, and may amount to torture. This will have considerable implications for policing practices, including training, equipment, and relevant instructions.

Moreover, this entails that certain weapons or riot control devices may be inherently cruel, inhuman or degrading, or (likely to be) used in a cruel, inhuman or degrading manner. As the report specifies, a weapon or device will be inherently cruel, inhuman or degrading, and therefore prohibited, if it is specifically designed, or is of a nature (that is, of no other practical use than) to employ unnecessary, excessive or otherwise arbitrary force, against persons.

You can find Dr Mavronicola’s underpinning research on the right not to be subjected to torture and related ill-treatment on her university profile page.